Apparatus and methods for regulating negative pressure in a negative pressure wound therapy system

Patent metadata

Field	Value
Publication number	US-11241338-B2
Application number	US-201615766576-A
Country	US
Kind code	B2
Filing date	Nov 1, 2016
Priority date	Nov 3, 2015
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

A pressure switch for controlling application of negative pressure to dressing disposed adjacent a tissue site is disclosed. The pressure switch comprises a body having a base, sidewalls extending from the base to an open end, and an inlet coupled to the dressing and forming a passage through the body. The pressure switch further comprises a diaphragm closing the open end of the sidewalls and forming a vacuum chamber with the body, wherein the inlet fluidly couples the vacuum chamber and the dressing. The pressure switch further comprises a valve disposed in the passage and configured to restrict the flow of gas through the passage so that a switch pressure developed in the vacuum chamber as a result of the application of negative pressure to the dressing lags a wound pressure at the tissue site to delay, wherein the diaphragm is adapted to be operatively responsive to the switch pressure to move between a relaxed position and a compressed position as the negative pressure increases and decreases. This pressure switch further comprises a switching element coupled to the diaphragm to turn on the negative pressure in the relaxed position and turn off the negative pressure in the compressed position. In another example, a method for controlling application of negative pressure to dressing disposed adjacent a tissue site using a pressure switch is disclosed. In another example, a system for applying negative pressure to a tissue site using a pressure switch is disclosed.

First claim

What is claimed is:

1. A system for applying negative pressure to a tissue site, comprising:
a dressing including a tissue interface adapted to contact the tissue site and a cover adapted to provide a fluid seal between a therapeutic environment including the tissue interface proximate one side of the cover and a local external environment on the other side of the cover;
a negative-pressure source fluidly coupled to the dressing and adapted to provide negative pressure to the therapeutic environment;
a pneumatic actuator having a body closed by a diaphragm forming a vacuum chamber with the body, an inlet coupled to the dressing and forming a passage through the body to fluidly couple the vacuum chamber and the therapeutic environment, the diaphragm adapted to move between a relaxed position and a compressed position in response to pressure in the vacuum chamber generated by the negative pressure;
a valve disposed in the passage and configured to restrict the flow of gas through the passage; and
a switching element operatively coupled to the diaphragm and adapted to turn on the negative-pressure source when the diaphragm is in the relaxed position and turn off the negative-pressure source when the diaphragm is in the compressed position.

2. The system of claim 1 , further comprising a coil spring having a first end coupled to the diaphragm and a second end coupled to the body of the actuator.

3. The system of claim 2 , wherein the diaphragm and the first end of the coil spring move between the relaxed position and the compressed position.

4. The system of claim 1 , wherein the body of the pneumatic actuator comprises a base and sidewalls extending from the base to an open end, and wherein the diaphragm closes the open end of the sidewalls.

5. The system of claim 4 , wherein the diaphragm comprises a center portion and a peripheral portion extending radially outwardly from the center portion to the open end of the sidewalls.

6. The system of claim 5 , wherein the center portion is a membrane and the peripheral portion comprises a flexible skirt.

7. The system of claim 5 , further comprising an elastic element having a first end coupled to the center portion of the diaphragm and a second end coupled to the base.

8. The system of claim 7 , wherein the elastic element is a coil spring.

9. The system of claim 1 , wherein the tissue interface is a manifold.

10. The system of claim 1 , further comprising a processor operatively coupled to the negative-pressure source to provide a target pressure to the therapeutic environment in a pressure control mode.

11. The system of claim 10 , wherein the pressure control mode is a continuous pressure mode.

12. The system of claim 10 , wherein the pressure control mode is an intermittent pressure mode.

13. The system of claim 1 , further comprising a processor operatively coupled to the negative-pressure source to provide a variable target pressure to the therapeutic environment in a dynamic pressure mode.

14. The system of claim 1 , further comprising a positive-pressure source fluidly coupled to the dressing for delivering a solution to the therapeutic environment and the tissue interface for a predetermined time.

15. The system of claim 14 , further comprising a processor operatively coupled to the positive-pressure source to provide the solution to the therapeutic environment in a predetermined dosage.

16. The system of claim 14 , further comprising a processor operatively coupled to the positive-pressure source to provide the solution to the therapeutic environment at a predetermined rate over time.

17. The system of claim 14 , further comprising a processor operatively coupled to the negative-pressure source and the positive-pressure source to provide negative pressure to the therapeutic environment prior to providing the solution to the therapeutic environment.

18. The system of claim 14 , further comprising a processor operatively coupled to the negative-pressure source and the positive-pressure source to provide negative pressure to the therapeutic environment while providing the solution to the therapeutic environment.

19. A pressure switch for controlling application of negative pressure to dressing disposed adjacent a tissue site, comprising:
a body having a base, sidewalls extending from the base to an open end, and an inlet coupled to the dressing and forming a passage through the body;
a diaphragm closing the open end of the sidewalls and forming a vacuum chamber with the body, wherein the inlet fluidly couples the vacuum chamber and the dressing;
a valve disposed in the passage and configured to restrict the flow of gas through the passage so that a switch pressure developed in the vacuum chamber as a result of the application of negative pressure to the dressing lags a wound pressure at the tissue site, wherein the diaphragm is adapted to be operatively responsive to the switch pressure to move between a relaxed position and a compressed position as the negative pressure increases and decreases; and
a switching element coupled to the diaphragm to turn on the negative pressure in the relaxed position and turn off the negative pressure in the compressed position.

20. The pressure switch of claim 19 , wherein the diaphragm comprises a center portion and a peripheral portion extending radially outwardly from the center portion to the open end of the sidewalls.

21. The pressure switch of claim 20 , wherein the center portion is a membrane and the peripheral portion comprises a flexible skirt.

22. The pressure switch of claim 20 , further comprising an elastic element having a first end coupled to the center portion of the diaphragm and a second end coupled to the base.

23. The pressure switch of claim 22 , wherein the elastic element is a coil spring.

24. The pressure switch of claim 19 , wherein the valve has an orifice with a diameter less that the diameter of the inlet.

25. The pressure switch of claim 24 , wherein the diameter of the orifice is sufficiently less than the diameter of the inlet to restrict the flow of gas through the passage.

26. The pressure switch of claim 19 , wherein the valve comprises a filter material that restrict the flow of gas through the passage.

27. The pressure switch of claim 19 , wherein the relaxed position corresponds to a minimum target pressure selected as the wound pressure in the compressed position corresponds to a maximum target pressure selected as the wound pressure.

28. The pressure switch of claim 19 , wherein the switching element is an electromechanical device.

29. The pressure switch of claim 28 , wherein the switching element is a single-pole, double-throw electromechanical switch.

30. The pressure switch of claim 28 , wherein the switching element comprises an actuation portion including an electrical contact having two ends wherein a first end is in a fixed position relative to the body and a second end having a contact tip, and a diaphragm portion having two electrical contacts in a fixed relationship with the diaphragm, wherein the contact tip of the actuation portion operatively contacts either one of the two electrical contacts of the diaphragm portion as the diaphragm moves between the relaxed position and the compressed position.

31. The pressure switch of claim 30 , wherein the switching element f

Assignees

• Kci Licensing Inc

Inventors

• Pratt Benjamin Andrew
• Beasley Michael Bernard
• Locke Christopher Brian
• Seddon James Killingworth

Classifications

• H01H35/34 Primary

  actuated by diaphragm · CPC title

• A61M1/966

  having a pressure sensor on or near the dressing · CPC title

• A61M1/92

  with liquid supply means · CPC title

• A61M1/74

  Suction control (underwater drainage A61M1/61) · CPC title

• A61M2205/3355

  Controlling downstream pump pressure · CPC title